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2.
J Gen Intern Med ; 36(7): 1914-1920, 2021 07.
Article in English | MEDLINE | ID: mdl-33483828

ABSTRACT

BACKGROUND: In several settings, a shorter time to diagnosis has been shown to lead to improved clinical outcomes. The implementation of a rapid laboratory testing allows for a pre-visit testing in the outpatient clinic, meaning that test results are available during the first outpatient visit. OBJECTIVE: To determine whether the pre-visit laboratory testing leads to a shorter time to diagnosis in the general internal medicine outpatient clinic. DESIGN: An "on-off" trial, allocating subjects to one of two treatment arms in consecutive alternating blocks. PARTICIPANTS: All new referrals to the internal medicine outpatient clinic of a university hospital were included, excluding second opinions. A total of 595 patients were eligible; one person declined to participate, leaving data from 594 patients for analysis. INTERVENTION: In the intervention group, patients had a standardized pre-visit laboratory testing before the first visit. MAIN MEASURES: The primary outcome was the time to diagnosis. Secondary outcomes were the correctness of the preliminary diagnosis on the first day, health care utilization, and patient and physician satisfaction. KEY RESULTS: There was no difference in time to diagnosis between the two groups (median 35 days vs 35 days; hazard ratio 1.03 [0.87-1.22]; p = .71). The pre-visit testing group had higher proportions of both correct preliminary diagnoses on day 1 (24% vs 14%; p = .003) and diagnostic workups being completed on day 1 (10% vs 3%; p < .001). The intervention group had more laboratory tests done (50.0 [interquartile range (IQR) 39.0-69.0] vs 43.0 [IQR 31.0-68.5]; p < .001). Otherwise, there were no differences between the groups. CONCLUSIONS: Pre-visit testing did not lead to a shorter overall time to diagnosis. However, a greater proportion of patients had a correct diagnosis on the first day. Further studies should focus on customizing pre-visit laboratory panels, to improve their efficacy. TRIAL REGISTRATION: NL5009.


Subject(s)
Ambulatory Care Facilities , Humans , Referral and Consultation
3.
Ann Med Surg (Lond) ; 51: 48-53, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32082564

ABSTRACT

BACKGROUND: To reduce overutilization of laboratory testing many interventions have been tried, but selecting the most effective intervention for a given setting is challenging. To be sustainable, interventions need to align with healthcare providers' needs and daily practices. This study aimed to assess the extent of overutilization and the perspectives of healthcare providers, which may be used to guide the choice of intervention. METHODS: The extent of inappropriate laboratory testing in internal medicine inpatients was evaluated using a database. Surveys and focus groups were used to investigate healthcare providers' perceptions on its causes and solutions. RESULTS: On average, patients had 5.7 laboratory orders done during the first week of admission, whereas guidelines advise performing laboratory testing no more than twice per week. Repeat testing of normal test results occurred in up to 85% of patients. The frequency of laboratory testing was underestimated by survey responders, even though the majority of responders (78%) thought that laboratory tests are ordered too frequently. Residents were considered to be most responsible for laboratory test ordering.The primary causes of overutilization discussed were personal factors, such as a lack of awareness and knowledge, as well as feelings of insecurity. Regarding possible solutions, residents generally recommended educational interventions, whereas specialists tended to favour technical solutions such as lockouts. CONCLUSION: Inappropriate laboratory testing is common in internal medicine. The most important causes are a lack of awareness and knowledge, especially in residents. The intervention most favoured by residents is education, suggesting educational interventions may be most applicable.

4.
Lupus ; 28(10): 1255-1260, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31357913

ABSTRACT

INTRODUCTION: C1q is an essential part of the classical pathway of complement activation. Genetic deficiencies, caused by homozygous mutations in one of the C1q genes, are rare and are strongly associated with development of systemic lupus erythematosus (SLE). Here we describe a C1q-deficient patient with a compound heterozygous mutation. MATERIAL AND METHODS: Serum was analysed with enzyme-linked immunosorbent assay (ELISA) and Western blot for the presence of C1q, and DNA and RNA sequencing was performed to identify the mutations and confirm that these were located on different chromosomes. RESULTS: The medical history of the patient includes SLE diagnosis at age 11 years with cerebral involvement at age 13, various infections, osteonecrosis and hemophagocytic syndrome. Using ELISA and Western blot, we confirmed the absence of C1q in the serum of the patient. Using DNA sequencing, two mutations in the C1QC gene were identified: c.100G > A p.(Gly34Arg) and c.205C > T p.(Arg69X). With RNA sequencing we confirmed that the mutations are located on different chromosomes. DISCUSSION: The patient described in this case report has a compound heterozygous mutation in C1QC resulting in C1q deficiency.


Subject(s)
Complement C1q/genetics , Lupus Erythematosus, Systemic/genetics , Mutation , Adult , Female , Homozygote , Humans , Sequence Analysis, DNA , Sequence Analysis, RNA
5.
Acute Med ; 17(4): 188-202, 2018.
Article in English | MEDLINE | ID: mdl-30882102

ABSTRACT

Of the warning scores in use for recognition of high-risk patients at the Emergency Department (ED), few incorporate laboratory results. Although hematological characteristics have shown prognostic value in small studies, large studies in elderly ED populations are lacking. We studied the association between blood cell and platelet counts and characteristics as well as C-reactive protein (CRP) at ED presentation with mortality in non-multitrauma patients ≥ 65 years. Comparison between survivors and non-survivors showed small, significant differences with AUROCs ranging between 56.6% and 65.2% for 30-day mortality. Combining parameters yielded an evident improvement (AUROC of 70.4%). Efforts should be pursued to study the added value of hematological parameters on top of clinical data when assessing patient risk.


Subject(s)
Emergency Service, Hospital , Hematology , Aged , C-Reactive Protein , Diagnostic Tests, Routine , Humans , Prognosis , Risk Assessment
6.
Eur J Surg Oncol ; 44(1): 67-73, 2018 01.
Article in English | MEDLINE | ID: mdl-29239733

ABSTRACT

BACKGROUND AND OBJECTIVES: Breast conserving surgery (BCS) can be challenging for large regions of ductal carcinoma in situ (DCIS), resulting in high rates of positive resection margins. Radioactive seed localization (RSL) using multiple radioactive iodine (125I) seeds can be used to bracket extensive DCIS (eDCIS). The goal of this study was to retrospectively compare the use of a single or multiple 125I seeds in RSL to enable BCS in patients with eDCIS. METHODS: All patients with eDCIS (area of ≥3.0 cm) who underwent either single or multiple-seed RSL between January 2008 and December 2016 were included. Patient, tumor and surgery characteristics were compared between both groups. Primary outcome measures were positive resection margin and re-operation rates. RESULTS: Respectively 48 and 58 patients with eDCIS underwent single- and multiple-seed RSL and subsequent BCS. The rate of positive resection margin (focal and more than focal) with single-seed RSL was 47.9%, compared to 29.3% with multiple-seed RSL (p = 0.06). The re-operation rate was 39.6% with single-seed RSL and 20.7% in the multiple-seed RSL group (p = 0.05). CONCLUSION: Multiple-seed RSL enables bracketing of large areas of DCIS, with the potential to decrease the high rate of positive resection margins in this patient group.


Subject(s)
Breast Neoplasms/surgery , Carcinoma, Intraductal, Noninfiltrating/surgery , Iodine Radioisotopes/therapeutic use , Mastectomy, Segmental/methods , Breast Neoplasms/diagnosis , Breast Neoplasms/radiotherapy , Carcinoma, Intraductal, Noninfiltrating/diagnosis , Carcinoma, Intraductal, Noninfiltrating/radiotherapy , Female , Humans , Mammography , Margins of Excision , Middle Aged , Neoplasm Staging , Retrospective Studies , Ultrasonography, Mammary
7.
Ned Tijdschr Geneeskd ; 161: D701, 2017.
Article in Dutch | MEDLINE | ID: mdl-28294924

ABSTRACT

OBJECTIVE: Is the simple mean of the costs per diabetes patient a suitable tool with which to compare care groups? Do the total costs of care per diabetes patient really give the best insight into care group performance? DESIGN: Cross-sectional, multi-level study. METHOD: The 2009 insurance claims of 104,544 diabetes patients managed by care groups in the Netherlands were analysed. The data were obtained from Vektis care information centre. For each care group we determined the mean costs per patient of all the curative care and diabetes-specific hospital care using the simple mean method, then repeated it using the 'generalized linear mixed model'. We also calculated for which proportion the differences found could be attributed to the care groups themselves. RESULTS: The mean costs of the total curative care per patient were €3,092 - €6,546; there were no significant differences between care groups. The mixed model method resulted in less variation (€2,884 - €3,511), and there were a few significant differences. We found a similar result for diabetes-specific hospital care and the ranking position of the care groups proved to be dependent on the method used. The care group effect was limited, although it was greater in the diabetes-specific hospital costs than in the total costs of curative care (6.7% vs. 0.4%). CONCLUSION: The method used to benchmark care groups carries considerable weight. Simply stated, determining the mean costs of care (still often done) leads to an overestimation of the differences between care groups. The generalized linear mixed model is more accurate and yields better comparisons. However, the fact remains that 'total costs of care' is a faulty indicator since care groups have little impact on them. A more informative indicator is 'costs of diabetes-specific hospital care' as these costs are more influenced by care groups.

8.
BJOG ; 122(9): 1252-8, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25515605

ABSTRACT

OBJECTIVE: Evidence suggests an association between vasomotor menopausal symptoms (VMSs), i.e. hot flushes and night sweats, and cardiovascular disease. However, the causal pathway is unclear. We investigated whether an unfavourable cardiovascular risk profile is a risk factor for VMS later in life. DESIGN: Retrospective cohort study. SETTING: Women aged 50-70 from the general population. POPULATION: The Prospect-European Prospective Investigation into Cancer and Nutrition (Prospect-EPIC) cohort is a population-based cohort of women who enrolled between 1993 and 1997. Follow-up questionnaires were sent at 5-year intervals for 15 years. Women who returned the third questionnaire, answered questions regarding lifetime VMS and did not report VMS prior to baseline were included in this study (n = 1295). METHODS: At baseline, the Framingham Risk Score (FRS) was determined. We used logistic regression analysis to calculate odds ratios (ORs) for the association between baseline FRS and incident VMS. MAIN OUTCOME MEASURE: Incident VMS. RESULTS: At baseline (mean age ± standard deviation, 52.2 ± 3.6 years), 21.2% had a FRS > 10%. During follow-up, 40.2% of women reported the onset of VMS. Adjusted for body mass index, physical activity, education and alcohol consumption, each point increase in FRS was associated with a decreased incidence of VMS [OR, 0.94 (95% CI, 0.91-0.97)]. Additional adjustment for menopausal status attenuated the OR to null [OR, 0.98 (95% CI, 0.95-1.01)]. None of the separate FRS variables were associated with VMS after adjustment for age. CONCLUSIONS: In our cohort, an unfavourable cardiovascular risk profile was not associated with VMS, and therefore we found no evidence for the involvement of a vascular mechanism in the etiology of VMS.


Subject(s)
Cardiovascular Diseases/physiopathology , Hot Flashes/physiopathology , Menopause , Vasomotor System/physiopathology , Cardiovascular Diseases/epidemiology , Cardiovascular Diseases/prevention & control , Female , Hot Flashes/epidemiology , Humans , Incidence , Middle Aged , Prospective Studies , Risk Factors , White People
9.
Clin Exp Immunol ; 171(2): 231-6, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23286950

ABSTRACT

Vitamin D has been shown to modulate innate immune responses in vitro and ex vivo; however, human in-vivo data are lacking. At high latitudes, seasonal vitamin D deficiency is common due to alternating ultraviolet (UV)-B radiation exposure. In the present study, we investigated whether levels of 25 hydroxyvitamin D(3) [25(OH)D(3) ] and its active metabolite 1,25 dihydroxyvitamin D(3) [1,25(OH)(2) D(3) ] are subject to seasonal variation and whether plasma levels of these vitamin D metabolites correlate with the in-vivo cytokine response during experimental human endotoxaemia [administration of lipopolysaccharide (LPS) in healthy volunteers]. Plasma levels of 25(OH)D(3) and 1,25(OH)(2) D(3) were determined in samples obtained just prior to administration of an intravenous bolus of 2 ng/kg LPS (derived from Escherichia coli O:113) in 112 healthy male volunteers. In the same subjects, plasma levels of the inflammatory cytokines tumour necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10 were analysed serially after endotoxin administration. Plasma levels of 1,25(OH)(2) D(3) , but not 25(OH)D(3) , were subject to significant seasonal variation, with lower levels in autumn and winter. 25(OH)D(3) and 1,25(OH)(2) D(3) levels did not correlate with plasma cytokine responses. Furthermore, 25(OH)D(3) deficient subjects (< 50 nmol/l) displayed an identical cytokine response compared with sufficient subjects. In conclusion, plasma levels of vitamin D are not correlated with the LPS-induced TNF, IL-6 and IL-10 cytokine response in humans in vivo. These findings question the direct role of vitamin D in modulation of the innate immune response.


Subject(s)
Calcifediol/metabolism , Calcitriol/metabolism , Cytokines/immunology , Endotoxemia/immunology , Escherichia coli/immunology , Vitamin D/immunology , Adult , Calcifediol/immunology , Calcitriol/immunology , Cytokines/blood , Humans , Immunity, Innate , Inflammation Mediators/metabolism , Lipopolysaccharides/immunology , Male , Seasons , Vitamin D/blood , Young Adult
10.
Neuroscience ; 210: 82-98, 2012 May 17.
Article in English | MEDLINE | ID: mdl-22406416

ABSTRACT

Neural precursor cells (NPCs) provide a cellular model to compare transduction efficiency and toxicity for a series of recombinant adeno-associated viruses (rAAVs). Results led to the choice of rAAV9 as a preferred candidate to transduce NPCs for in vivo transplantation. Importantly, transduction promoted a neuronal phenotype characterized by neurofilament M (NFM) with a concomitant decrease in the embryonic marker, nestin, without significant change in glial fibrillary acidic protein (GFAP). In marked contrast to recent studies for induced pluripotent stem cells (iPSCs), exposure to rAAVs is non-immunogenic and these do not result in genetic abnormalities, thus bolstering the earlier use of NPCs such as those isolated from E13 murine cells for clinical applications. Mechanisms of cellular interactions were explored by treatment with genistein, a pan-specific inhibitor of protein receptor tyrosine kinases (PRTKs) that blocked the transduction and differentiation, thus implying a central role for this pathway for inducing infectivity along with observed phenotypic changes and as a method for drug design. Implantation of transduced NPCs into adult mouse hippocampus survived up to 28 days producing a time line for targeting or migration to dentate gyrus and CA3-1 compatible with future clinical applications. Furthermore, a majority showed commitment to highly differentiated neuronal phenotypes. Lack of toxicity and immune response of rAAVs plus ability for expansion of NPCs in vitro auger well for their isolation and suggest potential therapeutic applications in repair or replacement of diseased neurons in neurodegeneration.


Subject(s)
Dependovirus/genetics , Genetic Vectors/physiology , Neural Stem Cells/cytology , Transduction, Genetic/methods , Animals , Cell Differentiation , Immunohistochemistry , Mice , Mice, Inbred C57BL , Microscopy, Confocal , Neural Stem Cells/metabolism , Neurofilament Proteins/biosynthesis , Phenotype , Stem Cell Transplantation/methods
11.
Neurology ; 71(7): 525-30, 2008 Aug 12.
Article in English | MEDLINE | ID: mdl-18695164

ABSTRACT

OBJECTIVE: There are concerns that generic and brand antiepileptic drugs (AEDs) may not be therapeutically equivalent. This study investigated how generic AED substitution may have negative consequences. METHODS: Sixty-nine of 150 physicians who participated in a large survey on generic AED substitution completed a case review form regarding a patient who experienced a loss of seizure control due to a generic AED. Nineteen were excluded from analysis. RESULTS: Fifty patients, well-controlled on a brand AED, subsequently experienced a breakthrough seizure or increased seizure frequency after switching to a generic without other provoking factors. AEDs included phenytoin (15 cases), valproic acid (14), carbamazepine (7), gabapentin (8), and zonisamide (8). Two patients were on a combination of two AEDs, both of which were switched to generics. In 26 cases serum AED levels were known both before and after generic substitution. Twenty-one had lower levels at the time of the breakthrough seizure on the generic medication. Loss of seizure control had a negative impact on quality of life, including loss of driving privileges (n = 30) and missed school/work days (n = 9). CONCLUSIONS: Changing from a brand antiepileptic drug (AED) to a generic may result in seizures. This raises the concern that current Food and Drug therapeutic equivalence testing regulations may not be adequate for AEDs and suggests that more clinical evidence is needed. Physicians, pharmacists, patients, and policy makers should be aware that for some patients there may be risks associated with switching from brand to generic AEDs.


Subject(s)
Anticonvulsants/pharmacokinetics , Anticonvulsants/therapeutic use , Drugs, Generic/pharmacokinetics , Epilepsy/drug therapy , Adult , Aged , Humans , Male , Middle Aged , Therapeutic Equivalency
13.
J Mol Neurosci ; 17(3): 351-9, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11859931

ABSTRACT

N-acetyl-L-histidine (NAH) and N-acetyl-L-aspartate (NAA) are representatives of two series of substances that are synthesized by neurons and other cells in the vertebrate central nervous system (CNS). Histidine containing homologs of NAH are beta-alanyl-L-histidine or carnosine (Carn) and gamma-aminobutyrl-L-histidine or homocarnosine (Hcarn). A homolog of NAA is N-acetylaspartylglutamate (NAAG). These substances belong to a unique group of osmolytes in that they are synthesized in cells that may not to be able to hydrolyze them, and are released in a regulated fashion to a second compartment where they can be rapidly hydrolyzed. In this investigation, the catabolic activities for NAH, Carn, and Hcarn in cultured macroglial cells and neurons have been measured, and the second compartment for NAH and Hcarn has been identified only with astrocytes. In addition, oligodendrocytes can only hydrolyze Carn, although Carn can also be hydrolyzed by astrocytes. Thus, astrocytes express hydrolytic activity against all three substrates, but oligodendrocytes can only act on Carn. The cellular separation of these hydrolytic enzyme activities, and the possible nature of the enzymes involved are discussed.


Subject(s)
Brain/metabolism , Carnosine/analogs & derivatives , Carnosine/metabolism , Histidine/analogs & derivatives , Histidine/metabolism , Amidohydrolases/metabolism , Animals , Brain/cytology , Brain/enzymology , Cells, Cultured , Chromatography, High Pressure Liquid , Hydrolysis , Neuroglia/metabolism , Neurons/metabolism , Oligodendroglia/metabolism , Rats
14.
Neurochem Res ; 26(12): 1311-20, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11885783

ABSTRACT

To provide an explanation for earlier paradoxical findings of lithium on survival of mature and immature neurons, this study monitors changes in cytosolic caspases in rat cerebellar granule cells (CGC) grown 2-7 days in vitro (DIV), or in murine E-17 cortical neurons. Data show Li+ protects mature 7-DIV CGC parallel to a decrease in proximal and distal caspases but increases levels for immature 2-DIV-CGC or E-17 cortical neurons. Caspases mirror viability based on morphological analyses (dye uptake, phase-contrast, DNA fragmentation), and suggest protection occurs by suppressing activation of a cascade resulting in distal effectors that destroy proteins essential for neuronal survival. Protection was dose-dependent with EC50 3.0 mM and extended to 64 h in K+-serum deprived apoptotic media. Neuronal extracts contain a spectrum of proximal (-2, -8, -9) and distal (-3, -6) caspases sensitive to Li+ on assay with preferred peptide substrates and by immunoblotting. The lack of direct effect on activated cytosols indicates Li+ acts upstream only on intact cells, at sites for recruitment of pivotal procaspases. Alterations of procaspase-9 p46 and membrane-bound cytochrome c (Apaf-1) point to interaction with an intrinsic Mt-mediated pathway as one of the targets. The opposite effects on caspases and viability of immature or embryological neurons point to existence of alternative pathways that alter during neurite outgrowth suggesting the use of Li+ as a probe to unravel events relevant to neurogenesis.


Subject(s)
Caspases/metabolism , Lithium/pharmacology , Neurons/drug effects , Neurons/physiology , Animals , Caspase Inhibitors , Cell Survival/drug effects , Cells, Cultured , Cellular Senescence , Cerebellum/cytology , Culture Media, Serum-Free/pharmacology , Potassium/pharmacology , Rats , Rats, Sprague-Dawley
15.
Ann Pharmacother ; 34(5): 639-45, 2000 May.
Article in English | MEDLINE | ID: mdl-10852093

ABSTRACT

OBJECTIVE: To present a review of the literature and research on the pharmacogenetics of congenital defects, with a focus on the need for predictive maternal genotype assays. DATA SOURCE: MEDLINE searches (January 1985-January 1999), past reference reviews, and unpublished research. STUDY SELECTION: Review of relevant human, animal, and basic science studies. DATA EXTRACTION: Data on research on polymorphisms, genotyping, cytochrome P450 enzyme systems, epoxide hydrolase, folate metabolism, metabolism of anticonvulsant medications, molecular genetics of neural tube defects, variations in drug metabolism, and environmental exposures were evaluated. DATA SYNTHESIS: Data synthesis includes not only a review of the literature but suggests ways such data might be used to facilitate the development of maternal genotype assays, with the goal of preventing birth defects. CONCLUSIONS: Individuals vary in how they metabolize drugs and handle toxic environmental exposures. In an ideal pregnancy, there is no or limited exposure to medications and environmental agents. However, in women with chronic medical conditions such as heart disease and seizures, this is often not possible. Unfortunately, no techniques have been available to identify those at risk in this population. Gene polymorphisms for a specific enzyme may result in an absence or reduction in the level of enzyme activity or in no change at all, with little effect on the structure/function of the gene product(s); they are not associated with clinical phenotypes in either the mother or the fetus. Other polymorphisms may be only markers. Thus, developing genotyping assays for women that are predictive of phenotype expression in the fetus is the key to screening for polymorphisms. As more mutations are identified and clinical, pharmacologic, biologic, and pharmacokinetic relationships are established, using these polymorphisms to develop a genotyping assay for women may become a clinical reality, possibly leading to preventive prepregnancy or prenatal treatment that may play an increasingly effective role in maternal care.


Subject(s)
Congenital Abnormalities/diagnosis , Fetus/abnormalities , Genetic Testing , Female , Genetic Markers , Humans , Mutation , Pharmacogenetics , Polymorphism, Genetic , Pregnancy
16.
Ann Neurol ; 47(2): 265-9, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10665503

ABSTRACT

Mutations in the X-linked doublecortin gene appear in many sporadic cases of double cortex (DC; also known as subcortical band heterotopia), a neuronal migration disorder causing epilepsy and mental retardation. The purpose of this study was to examine why a significant percentage of sporadic DC patients had been found not to harbor doublecortin mutations and to determine whether clinical features or magnetic resonance imaging scan appearance could distinguish between patients with and without doublecortin mutations. Magnetic resonance imaging scan analysis differentiated patients into the following four groups: anterior biased/global DC with doublecortin mutation (16 of 30; 53%), anterior biased/global DC without mutation (8 of 30; 27%), posterior biased DC without mutation (3 of 30; 10%), and limited/unilateral DC without mutation (3 of 30; 10%). The presence of these atypical phenotypes suggests that other genetic loci or mosaicism at the doublecortin locus may be responsible for this diversity of DC cases.


Subject(s)
Cerebral Cortex/abnormalities , Cerebral Cortex/pathology , Microtubule-Associated Proteins , Mutation , Neuropeptides/genetics , Adolescent , Adult , Brain/pathology , Child , Child, Preschool , Doublecortin Domain Proteins , Female , Humans , Magnetic Resonance Imaging
17.
Neurochem Res ; 24(9): 1107-15, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10485581

ABSTRACT

Ethanol significantly enhances cell death of differentiated rat cerebellar granule neurons on culture in a serum-free medium containing a depolarizing concentration of KCl (25 mM), 5 microM MK-801 (an NMDA receptor antagonist), and 20-200 mM ethanol for 1-4 days. Cell death augmented by ethanol was concentration- and time-dependent with neurons displaying hallmark apoptotic morphology and DNA fragmentation that correlated with the activation of cytosolic caspase-3. Inclusion of 5 microM MK-801 or 100 microM glycine in culture media did not alter rates of cell death indicating ethanol toxicity is mediated via an NMDA receptor-independent pathway. Preincubation with 50 microM gangliosides GM1, GD1a, GD1b or GT1b for 2 h, or preincubation with 10 microM LIGA20 (a semisynthetic GM1 with N-dichloroacetylsphingosine) for 10 min, attenuated caspase-3 activity and ethanol-induced cell death. Data show native gangliosides and a synthetic derivative are potently neuroprotective in this model of ethanol toxicity, and potentially serve as useful probes to further unravel the mechanisms relevant to neuronal apoptosis.


Subject(s)
Apoptosis/drug effects , Cerebellum/drug effects , Ethanol/toxicity , Gangliosides/pharmacology , Neurons/drug effects , Animals , Caspase 3 , Caspases/metabolism , Cells, Cultured , Cerebellum/cytology , Cytoplasmic Granules/drug effects , Dizocilpine Maleate/pharmacology , Enzyme Activation , G(M1) Ganglioside/analogs & derivatives , G(M1) Ganglioside/pharmacology , Glycine/pharmacology , Rats , Rats, Sprague-Dawley , Sphingosine/analogs & derivatives , Sphingosine/pharmacology
18.
Neurochem Int ; 35(3): 195-220, 1999 Sep.
Article in English | MEDLINE | ID: mdl-10458652

ABSTRACT

In view of a large and growing literature, this overview emphasizes recent advances in neuronal caspases and their role in cell death. To provide historical perspective, morphology and methods are surveyed with emphasis on early studies on interleukin converting enzyme (ICE) as a prototype for identifying zymogen subunits. The unexpected homology of ICE (caspase-1) to Caenorhabditis elegans death gene CED-3 provided early clues linking caspases to programmed cell death, and led later to discovery of bcl-2 proteins (CED-9 homologs) and 'apoptosis associated factors' (Apafs). Availability of substrates, inhibitors, and cDNAs led to identification of up to 16 caspases as a new superfamily of unique cysteine proteinases targeting Asp groups. Those acting as putative death effectors dismantle neurons by catabolism of proteins essential for survival. Caspases degrade amyloid precursor protein (APP), presenilins (PS1, PS2), tau, and huntingtin, raising questions on their role in neurodegeneration. Brain contains 'inhibitors of apoptosis proteins' (IAPs) survivin and NAIP associated also with some neuronal disorders. Apoptotic stress in neurons initiates a chain of events leading to activation of distal caspases by pathways that remain to be fully mapped. Neuronal caspases play multiple roles for initiation and execution of cell death, for morphogenesis, and in non-mitotic neurons for homeostasis. Recent studies focus on cytochrome c as pivotal in mediating conversion of procaspase-9 as a major initiator for apoptosis. Identifying signaling pathways and related events paves the way to design useful therapeutic remedies to prevent neuronal loss in disease or aging.


Subject(s)
Apoptosis , Caspases/metabolism , Neurons/enzymology , Animals , Cysteine Proteinase Inhibitors/pharmacology , Mice , Mice, Knockout , Mice, Transgenic , Models, Neurological , Neurons/cytology , Substrate Specificity
20.
Ann Neurol ; 45(2): 146-53, 1999 Feb.
Article in English | MEDLINE | ID: mdl-9989615

ABSTRACT

Mutations in the X-linked gene doublecortin, which encodes a protein with no dear structural homologues, are found in pedigrees in which affected females show "double cortex" syndrome (DC; also known as subcortical band heterotopia or laminar heterotopia) and affected males show X-linked lissencephaly. Mutations in doublecortin also cause sporadic DC in females. To determine the incidence of doublecortin mutations in DC, we investigated a cohort of eight pedigrees and 47 sporadic patients with DC for mutations in the doublecortin open reading frame as assessed by single-stranded conformational polymorphism analysis. Mutations were identified in each of the eight DC pedigrees (100%), and in 18 of the 47 sporadic DC patients (38%). Identified mutations were of two types, protein truncation mutations and single amino acid substitution mutations. However, pedigrees with DC displayed almost exclusively single amino acid substitution mutations, suggesting that patients with these mutations may have less of a reproductive disadvantage versus those patients with protein truncation mutations. Single amino acid substitution mutations were tightly clustered in two regions of the open reading frame, suggesting that these two regions are critical for the function of the Doublecortin protein.


Subject(s)
Brain Diseases/genetics , Cerebral Cortex/abnormalities , X Chromosome/genetics , Brain Diseases/pathology , Cerebral Cortex/pathology , DNA/analysis , Female , Humans , Magnetic Resonance Imaging , Male , Pedigree , Point Mutation , Polymorphism, Single-Stranded Conformational , Syndrome
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